In some refrigeration systems, a line of products to be for example refrigerated is moved through the refrigeration system, along a spiral or helical pathway through the cold or chilling region. Systems in which products to be refrigerated follow a spiral or helical pathway through the cold region are conventionally termed spiral refrigeration systems. Related systems may be used to heat products.
One type of refrigeration system used in the industry to remove heat from products is a spiral refrigeration system. Unless otherwise noted, as used herein, “spiral” refers to both spiral and helix forms.
A single pass configuration spiral refrigeration system is one in which a gas such as cryogen is directed by fans to flow among the products to be cooled. The gas is then returned from the products to the fans through return gas conveyances in the system. In existing single pass systems, the return gas conveyances may consist of ductwork which do not contain products from which it is desirable to remove heat. Since there are no products to be cooled along the return ductwork path, single pass systems lose cooling capacity due to less efficient use of process volume along with the inefficiencies associated with maintaining the environment in this ductwork space. In addition, the large external return gas conveyors and ductwork add bulk and footprint area to known systems; further reducing cost-effectiveness of such systems.
It therefore remains desirable to provide for a more efficient system to cool and/or chill products, and heat and/or cook products in a spiral heat transfer system.